High force of sea waves is a huge renewable energy resource and sea waves, will play an important role in tomorrow's electricity production. This paper presents a new method for converting sea wave energy to continuously crank shaft motive force by a new apparatus named engine for producing energy from sea waves. There by, this apparatus can be used for producing AC electricity from sea waves, which is also economically important in sea wave energy converting. Besides, this apparatus generates positive moment (crank shaft moment) from sea wave and this makes that, EPEW's RMS moment be more than other devices. Against of other devices EPEW in three dimensions contact with sea waves and absorbs more energy in length of sea shore. In this paper we design, simulate and calculate amount of energy for this new WEC.