A bipolar transistor and a radio frequency amplifier circuit capable of preventing thermal runaway in the bipolar transistor without affecting the radio frequency amplifier circuit, which includes: a direct-current (DC) bias terminal to which a DC bias is supplied; a DC base electrode connected to the DC terminal; a radio frequency (RF) power terminal to which a radio frequency signal is supplied; an RF base electrode connected to the RF terminal; and a base layer connected to the DC base electrode and the RF base electrode.