Provided is a plug conversion adapter which can easily open a shutter even in the case of a BF type AC power plug socket and can also be even in other types of AC power plug sockets. The interval between a pair of electrode pins can be controlled by operating a pair of first movable members, and thus the plug conversion adapter can be used in a larger number of types of AC power plug sockets. The interval between the pair of first movable members is restricted by a second movable member at a maximum, and thus a shutter can also be easily opened even in the case of an AC power plug socket that has a structure in which the shutter is opened by pushing both corners of the pair of electrode pin insertion openings.
