NOVELTY - The system (1) has an ocean wave energy absorber (10) that is formed by drilling a hole. One end of hole is opened under a sea surface, and other end is opened on land adjacent to bedrock (L). The ocean wave energy absorber has an air chamber (13) at which a pneumatic pressure is varied by vertical motion of sea level (14a) of hole. A buffer tank (20) moderates fine pressure fluctuation of reciprocation airflow in land side opening portion (12) of hole, and supplies reciprocation airflow to electric power generating apparatus (31) to generate electricity.    USE - Fixed oscillating water column type wave-powered-electricity generation system.    ADVANTAGE - Since the ocean wave energy absorber is formed adjacent to coastal ground or bedrock, the ocean wave energy absorber can be adapted for many topographies and environments of seashore region. The ocean wave absorber can exhibit outstanding resistance-strength and durability. Damage cause to ocean wave absorber due to external force such as abnormal wave and tsunami can be prevented. Need of constructing large-scale artificial structures such as breakwater and Caisson on underwater of offshore or area along the shore is eliminated, so that the material cost required for assembling wave-powered-electricity generation system is significantly reduced. The construction cost can be reduced significantly.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) method for assembling wave-powered-electricity generation system; and    (2) electric power generation method.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of the fixed oscillating water column type wave-powered-electricity-generation system.    Fixed oscillating water column type wave-powered-electricity generation system (1)    Ocean wave energy absorber (10)    Land side opening portion of hole (12)    Air chamber (13)    Sea level (14a)    Buffer tank (20)    Electric power generating apparatus (31)    Bedrock (L)