A portable terminal includes a first casing having a first wiring board, a first operation portion, and an accommodating portion opened in its peripheral surface, and a second casing configured to be accommodated in the accommodating portion through the opening and having a second wiring board and a second operation portion. A casing movement guiding/supporting mechanism is interposed between one side portion of the first casing and that of the second casing in one direction intersecting a moving locus of the second casing between a retracted position and an extended position in relation to the accommodating portion, and supports the second casing to be movable linearly between the retracted and extended positions. The second casing is selectively locked at the retracted position by a locking mechanism. A battery for supplying electricity to the wiring boards is accommodated in an accommodating chamber in at least one of the casings.