An electric stapler includes a staple sheet storage portion for storing a stack of staple sheets, a magazine storage portion disposed on a rear side of the staple sheet storage portion to store a staple magazine, a first staple feed mechanism operable to pull out a staple sheet from the staple magazine and to feed the staple sheet to the staple sheet storage portion, and a second staple feed mechanism operable to pull out the staple sheet from the staple sheet storage portion and to feed the staple sheet to a driver unit. According to this configuration, a continuous binding processing beyond a capacity of the staple magazine becomes possible by suitably replacing the staple magazine.