NOVELTY - The method involves supplying remainder gas in reaction container (1) from another gas supply portion, when supplying gas of one portion in reaction container from one gas supply portion. An impeller (8) is rotated, and airflow is produced, when source material of liquid is heated, and when source material is vaporized and supplied in container by one gas supply portion. A gas passage by which gas in container flows inside tubular portion (3) from opening portion of other end side of tubular portion, and flows out of opening portion of one end side, is formed.    USE - Reaction method of reacting multiple gases such as selenium gas and hydrogen gas (all claimed) for manufacturing hydrogen selenide for use as raw material of copper indium gallium selenide (CIGS) type solar cell.    ADVANTAGE - Since multiple types of gases are made to react easily, the production amount of the target compound per unit time is increased.    DETAILED DESCRIPTION - The method involves arranging impeller which makes inside of tubular portion to produce airflow moves to one end side from other end side of tubular portion, inside tubular portion, when installing the tubular portion which is provided with an opening portion at both ends in the reaction container. The source material is arranged on the inside of the reaction container to vaporize within the reaction container. The airflow which rotates the impeller and faces the source material is produced, when the source material is arranged on a bottom portion inside of the reaction container, and is vaporized within the reaction container. Another gas supply portion is provided with several gas supply ports (2a) which supply the remainder gas in the reaction container. One portion of gas is selenium (10), and the remainder gas is hydrogen gas. An INDEPENDENT CLAIM is included for a reaction apparatus has one gas supply portion that is equipped with a raw material accommodating portion (6) which accommodates the source material of the liquid used as the generation source of one portion of gas, and a heating portion which heats the raw material accommodating portion and vaporizes the source material. The raw material accommodating portion is provided inside the reaction container. The raw material accommodating portion is provided in a bottom portion inside of the reaction container, and the tubular portion is installed toward the raw material accommodating portion in the opening portion of one end side. Another gas supply portion is provided with several gas supply ports which supply the remainder gas in the reaction container.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of the reaction apparatus.    Reaction container (1)    Gas supply port (2a)    Tubular portion (3)    Impeller (8)    Selenium (10)