An input device including a frame in the form of a rectangular parallelepiped body which is supported by a base and which is movable between a first angular position in which an angle of a lower surface of the frame with respect to a horizontal upper surface of the base is smaller than a predetermined threshold value, and a second angular position in which the angle of the lower surface of the frame as seen in the first angular position with respect to the horizontal upper surface of the base is not smaller than the threshold value, a first input portion disposed on an upper surface of the frame as seen when the frame has a horizontal posture in the first angular position, in which a lower surface of the frame is parallel to the horizontal upper surface of the base, a second input portion disposed on a side surface of the frame as seen when the frame has the horizontal posture; and a detecting portion configured to detect an operation by an operator of the input device on at least one of the first and second input portions.