In a vehicular portable device, a display unit is controlled to display an icon representing an instruction to an in-vehicle device when detecting that an acceleration equal to or greater than an activation threshold occurs in the vehicular portable device, a pressing force at an icon selection position, which is a position where the icon is selected by a touch sensor, is detected, and a control signal instructing execution of a command corresponding to the icon being selected is transmitted based on detection of the pressing force in a state where the icon is selected.