In a multi-channel SQUID fluxmeter for detecting magnetic flux signals by use of an array of SQUID flux sensors each comprising a digital SQUID for providing a pulse output, multiplexers and the like are appropriately used to allow pulse signals output from the SQUID flux sensors to be switched on a time series basis in order to obtain a magnetic flux signal for each channel. Thus, only one processing circuit need to be provided for a large number of SQUID flux sensors, thus reducing the scale of the fluxmeter and making the device small.