A solenoid-type probe coil wherein superconductive thin film is used,
whose quality factor is high, and which is put in an uniform magnetic
field and occupies a small space is provided. For that purpose, the coil
is made by piling up, in generally parallel, two or more substrates on
which superconductive film is formed and connecting superconductors and
normal-metal thin films through capacitance or low contact resistance.