A video signal processing device is a video signal processing device for converting an input first video signal to a second video signal, and inputting to a display panel, the video signal processing device including an input unit for receiving an input of a set value of the second video signal to be converted and output in correspondence to a signal level for each of a plurality of sample points of the signal level of the first video signal; a calculating unit for interpolation calculating the signal level of the second video signal to be converted and output for the signal level between each sample points; and a control unit for transferring a conversion table including a set value of the second video signal for each sample point of the first video signal and an interpolation calculated interpolation value between each sample points to a memory unit; wherein the memory unit converts to the second video signal of a corresponding signal level based on the conversion table according to the signal level of the input first video signal, and outputs the second video signal.