A game operating device (controller) includes a longitudinal housing, and a holding portion held by hand to be wrapped by its palm it is formed in the housing. A direction switch is provided on an upper surface at a position where it can be operated by thumb of the hand holding the holding portion, and a start switch and a select switch are provided backward thereof. An X button 46 and a Y button are further arranged in line on the upper surface of the housing. An imaging information arithmetic unit is provided at a front end of the housing in a longitudinal direction in such a manner that an imaging device thereof is exposed from a front-end surface. A concave portion is formed on a lower surface at a position corresponding to the direction switch. The concave portion includes a valley and two inclined surfaces. An A button capable of being operated by index finger of the hand holding the holding portion is provided on the backward inclined surface. By processing an image signal obtained by imaging an infrared ray from LED modules by the imaging device, it is possible to obtain an operation signal varying according to a position and/or attitude of the controller.