To perform sound field control so that a listener may obtain a moderate feeling of spread of sound while suppressing costs.

This on-vehicle sound field controller is constituted so that a sound volume adjustment part performs balance adjustment of addition/subtraction between an L signal and an R signal, an addition part generates an addition signal, a subtraction part generates a subtraction signal, a filter processing part attenuates low frequency bands of the addition signal and the subtraction signal, a delay adjustment part adjusts delay amounts of the addition signal and the subtraction signal, an output signal synthesis part synthesizes the addition signal with the subtraction signal to generate an output signal, an equalizer processing part smooths frequency characteristics of the output signal, and the output signal is output using a ceiling material of a vehicle interior as a diaphragm by a single exciter.