A reciprocating type electric shaver comprises an inner-blade mount holding many inner blades and connected to a first driver-element converting rotary motion of a motor into reciprocating motions and an outer blade connected to a second driver-element reciprocated at a mechanical phase reverse to the first driver-element so that the inner blades and outer blade can slidably engage with each other mutually at mechanically reverse phase and the relative momentum of the outer blade with respect to the inner blades can be enlarged.