A wave power utilization device comprising: a wave receiving box having a wave receiving box inlet that receives push and pull of waves of seawater , and having a space filled with the seawater that flows in from the wave receiving box inlet ; a hollow compression pipe connected to communicate with an inside of the wave receiving box , the hollow compression pipe having an upper opening and a lower opening which is set to have a wider flow path cross-sectional area than a flow path cross-sectional area of the upper opening, the hollow compression pipe including a tapered section , a wave drawing section , and an air compressing section , the tapered section connecting the lower opening and the upper opening to each other in a tapered shape, the wave drawing section drawing the waves drawn into the wave receiving box through the tapered section , the air compressing section compressing air by the drawn waves; a gas-liquid introduction on-off valve which is connected to an upper part of the wave drawing section , and performs an opening operation to allow the air or the seawater to flow in and out; an air discharge pipe connected to an upper part of the air compressing section and having a check valve that allows a flow of the air only in a downstream direction from the air compressing section ; a compressed air storage tank connected to a downstream side of a flow path of the air discharge pipe , and filled with the air compressed by the air compressing section ; an air introduction unit which introduces the air into the air compressing section ; an air introduction pipe which connects the air introduction unit and the air compressing section to each other; and an air introduction on-off valve provided in a middle of the air introduction pipe and capable of introducing the air from the air introduction unit into the air compressing section during an opening operation. a wave receiving box having a wave receiving box inlet that receives push and pull of waves of seawater , and having a space filled with the seawater that flows in from the wave receiving box inlet ; a hollow compression pipe connected to communicate with an inside of the wave receiving box , the hollow compression pipe having an upper opening and a lower opening which is set to have a wider flow path cross-sectional area than a flow path cross-sectional area of the upper opening, the hollow compression pipe including a tapered section , a wave drawing section , and an air compressing section , the tapered section connecting the lower opening and the upper opening to each other in a tapered shape, the wave drawing section drawing the waves drawn into the wave receiving box through the tapered section , the air compressing section compressing air by the drawn waves; a gas-liquid introduction on-off valve which is connected to an upper part of the wave drawing section , and performs an opening operation to allow the air or the seawater to flow in and out; an air discharge pipe connected to an upper part of the air compressing section and having a check valve that allows a flow of the air only in a downstream direction from the air compressing section ; a compressed air storage tank connected to a downstream side of a flow path of the air discharge pipe , and filled with the air compressed by the air compressing section ; an air introduction unit which introduces the air into the air compressing section ; an air introduction pipe which connects the air introduction unit and the air compressing section to each other; and an air introduction on-off valve provided in a middle of the air introduction pipe and capable of introducing the air from the air introduction unit into the air compressing section during an opening operation. <EOS>