A metal detector for control of protected access comprises two oblong shape vertical housings (10, 12), a structure (14) connecting the upper part of the vertical housings (10, 12) and emitting and receiving electrical coils (3, 5) provided in the housings (10, 12). Each of the two housings (10, 12) comprises two separate emitting (3) and/or receiving (5) coils. The coils operate so that each of the two housings (10, 12) comprises one emitting coil (TX) and one receiving coil (RX). The metal detector further comprises a controller for controlling operation of the emitting and receiving coils, so that when an emitting coil (TX1, TX2) provided in a housing (10, 12) is active, the two receiving coils (RX1, RX2) provided respectively in both the two housings are also simultaneously or subsequently active.