An amplitude modulator is disclosed which has first and second differential pairs of transistors whose bases are supplied with a carrier signal, and a third differential pair of transistors whose collectors are respectively connected to the common emitters of the first and second differential pairs of transistors and of which one transistor is supplied at a base with a modulating signal. The emitters of the first differential pair of transistors are connected together through corresponding resistors. The collectors of two transistors which are included in the first and second differential pair of transistors and of which the bases are connected together and further connected to a load resistor.