When measuring steady-state visual-evoked potentials (SSVEPs) under noncontact conditions through a headrest cover and hair, signal attenuation or loss can occur due to increased coupling impedance. This study introduces a capacitance multiplier (CM) to enable noncontact SSVEP measurement by effectively amplifying the coupling capacitance. In measurements using a physical model, the introduction of the CM resulted in a 7.1 dB increase in signal-to-noise ratio. In experiments with five participants using a headrest-type electroencephalogram system equipped with cloth electrodes and the CM, a mean SSVEP detection success rate of 76% was achieved.