According to a driving method of a matrix-type display device of the present invention, a reference clock signal supplied by a reference clock oscillator is divided by a plurality of frequency dividing circuits, so that division clock signals are obtained. One among the division clock signals is selected by a switching operation by a switching circuit, and the selected division clock signal is outputted as a sampling clock signal to a row electrode driving circuit. Timings for the switching operation of the switching circuit are controlled by a switching control circuit in accordance with a horizontal synchronization signal and the reference clock signal. One or more of the frequency dividing circuits outputs a division clock signal having unequal clocks, when necessary. By thus arranging the division clock signals so that they have unequal clocks, it is allowed to set N of the division ratio 1/N to a value other than an integral number. Therefore, it is possible to set the division ratios close to each other, and hence, it is ensured that the reference clock signal has a lower frequency.