An energy concentration device includes a pneumatic cylinder that allows for contact with waving sea water of the nature to make a float device to drive a piston rod to achieve an effect of up and down piston movement so as to realize an effect of pressurization of air inside the pneumatic cylinder, whereby the air may achieve an effect of increase of pressurization level through multi-staged pressurization and an effect of accumulation by being stored in a high-pressure air storage device for the purposes of electrical power generation with the pressurized air and supplying pneumatic power required by other applications, such as automobiles, motorcycles, buses, and factories and also for supplying of pneumatic power to household devices, such as household appliances and pneumatically-operating doors.