[Problems] A portable mobile apparatus where two magnetism detecting unit and a reduced number of magnets can specify in which of the following four states the housings of the apparatus are: an open state where the housings are opened, a closed state where the housings are closed, a reversed display state where the housings are closed with a display reversed to face the outside, and a 90-degree state where the display is turned 90 degrees in the reversed display state.[Means of Solving Problems] The portable mobile apparatus has a display housing (11), an operation housing (21), a universal hinge (30) that enables both housings (11, 21) to be opened and closed at a connection end and enables the display housing (11) to rotate about an axis (B) that is normal to a display surface (11A) and about an axis (C) that is in parallel with the display surface (11A), a first magnet (12) and a second magnet (13) that are installed at the display housing (11), a first Hall IC (22) and a second Hall IC (23) that are installed at the operation housing (21) so as to correspond to the magnets (12, 13), and state determination unit (35) for determining each of the open/close states of the display housing (11) and the operation housing (21) based on detection information from the Hall ICs (22, 23).