NOVELTY - The office building (100) has a building segment (110) that is provided with a top portion (120). A thin film solar cell (130) is arranged on the top portion of the building segment. The thin film solar cell which absorbs a green light, a blue light, and an ultraviolet light, converts them into electrical energy, and reflects a portion of infrared light and ultraviolet light, such that red light, orange light, and yellow light pass through thin film solar cell, and reach inside of building segment.    USE - Office building for use as office room, communication machine room, or base station house, with transparent top portion for regulating indoor temperature and lighting.    ADVANTAGE - The top portion of the building segment is provided with thin film solar cells, so that the effects of lighting, energy saving, and temperature regulation are achieved. The thin film solar cell can be used as building material for the top portion of the building segment, so as to provide illumination when the sunlight is sufficient. The top portion of the building segment can be a detachable and replaceable roof structure, such that thin film solar cells can easily be replaced. Since some of the infrared light and ultraviolet light are reflected by the thin film solar cell, the rate of temperature increase inside the base station house can be reduced, thus the internal temperature can be regulated effectively in cooperation with air conditioners. Thus the expense of electricity for the air conditioner is considerably saved. The office building is provided with power supply device, so that when the power supply is interrupted, the power supply device can be activated immediately to supply the power required, so as to maintain the normal operations of the communication equipment. The air conditioner is provided to regulate room temperature, and that is located in a sentry-box-shaped building segment in regulating its inner temperature, and in cooperation with the functions of thin film solar cells of reflecting portion of the infrared light and ultraviolet light, so that temperature in the building segment can be maintained at a lower temperature. The power source module and the thin film solar cells can supply power to the air conditioner, so as to save air conditioning expense on electricity. The office building is also provided with several light-emitting-diodes for illumination at night. The light-emitting-diodes are arranged on the top portion of the building segment, such that when in sunny weather and broad daylight, the portion of sunlight passing through the transparent thin film solar cells can be used for internal illumination of a sentry-box-shaped building segment, and while in cloudy weather or at night, light-emitting-diodes can replace light bulbs in providing sufficient illumination inside the building segment, so that maintenance staff can carry on repair and/or maintenance of communication equipment at night. The thin film solar cells can also be connected electrically to the light-emitting-diodes for providing them with the converted electricity. The thin film solar cells are provided on the top portion of a building segment, such that when sunlight irradiates on the top portion of the building segment, the thin film solar cells absorb the green light, blue light, and ultraviolet light in the sunlight, and convert them into electrical energy, and then provide it to the power storage device, air conditioner, or communication equipment, etc, in the office building, so as to save expense spent on electricity. Since some of the infrared light and ultraviolet light are reflected by the thin film solar cell, the rate of temperature increase inside the base station house can be reduced, thus the internal temperature can be regulated effectively in cooperation with an air conditioner, and the expense of electricity for the air conditioner is saved.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic perspective view of the office building with transparent top portion.    Office building (100)    Communication equipment (105)    Building segment (110)    Top portion (120)    Thin film solar cell (130)