A diversity receiver capable of controlling start/stop of diversity reception under a switching condition according to the individual performance or the use environment, and a receiving-mode switching method. An input section (109) can select one of a diversity receiving mode constantly using two receiving systems, a single receiving mode constantly using a single receiving system, and an automatic control receiving mode for selecting the diversity receiving mode or the single receiving mode according to their receiving states and specifies the mode that the user uses. A control section (107) determines a selection determining criterion used in the automatic control receiving mode according to mode selection information on the other two modes.; If the diversity reception is frequently selected, the control section changes the determining criterion to the one under which switching to the diversity reception is frequently made. If the single reception is frequently switched, the control section changes the determining criterion to the one under which switching to the single reception is frequently made.