A manipulating foot pedal device used with a video game machine or the like is operable to provide a three-dimensional operation. The device includes a base member movable in a forward/backward direction relative. A rotatable member is mounted on a top of the base member and rotatable about a first axis extending in a direction perpendicular to the forward/backward direction; a pivotal member mounted on a top of the rotatable member and pivotable about a second axis extending in a direction perpendicular to the first axis. The device further includes first, second, and third detectors operable to detect a moved amount of the base member, a rotated amount of the rotatable member, and a pivoted amount of the pivotal member.