A prove apparatus includes a first and a second loading port for mounting therein two carriers facing each other, a wafer transfer mechanism having a rotation center between the loading ports, and a first and a second inspection unit being symmetrical to each other and disposed in accordance with the arrangement of the loading ports. In this configuration, wafers are directly transferred between the carrier and a wafer chuck of the inspection unit by the wafer transfer mechanism. The wafer transfer mechanism has three arms for unloading two wafers from the carrier. The prove apparatus has a compact size and achieves a high throughput.