A heelless instrument pedal device includes a bottom board and a pedal board. The bottom board is in connection with an instrument support and has two pivotal connection elements protruding upwards with a ball shape. The rear bottom surface of the pedal board has a pivotal connection base corresponding to the pivotal connection elements. The pedal board is connected to the pivotal connection elements on the bottom board using the pivotal connection base. Thus, the pedal board can swing in the direction of the force applied by the user's foot. The front end of the pedal board has a linking element, so that the linking element moves as the pedal board swings with respect to the pivotal connection elements.