The invention relates to an r.f. SQUID with a tank circuit. It is the aim of the invention to provide such a SQUID in which the variability and reliability of the connection betwen the SQUID and the tank circuit are improved over prior art SQUIDs without adversely affecting the resonant frequency and quality of the SQUID. To this end, for the construction of the tank circuit there is a metallic conductive layer on a substrate which is structured in such a way that at least one lateral flat capacitive structure is bonded to a lateral elongated inductive structure. Such a tank circuit produced by the planar layer method provides the desired variability in the connection of the tank circuit to the SQUID by the flip-chip method on a separate substrate, with distance means.
