Electromagnetic relay having a coil-wound bobbin with flanges at each end, a reed mounted on one flange and extending through the bobbin, fixed contacts mounted on the other flange cooperating with a free end of the reed, and a casing formed by a base and a cover. An upwardly projecting peripheral wall is provided on the base, and the lower edge of the cover engages the peripheral wall. Coil, reed and contact terminals extend through bores formed in the casing base. Grooves in the lower side of the base communicate with the bores and with the lower ends of passages which emerge at the peripheral wall. Sealant filled in the grooves simultaneously seals the terminals in the bores and the cover to the base. When the cover engages the interior of the peripheral wall, webs provided on the upper side of the casing base confine the sealant to the bores and to pockets provided at the outer side of the cover. The bobbin flange interior has a separator against which the fixed contacts abut to define the spacing between the fixed contacts. The separator also defines the spacing between the free end of the reed and a permanent magnet which cooperates with pole shoes connected to the fixed contacts.