To manufacture a case type alloy temperature fuse having an operation temperature of 190°C to 240°C at an excellent yield by providing a heat resistance corresponding to the operation temperature.

Flux 3 is applied to a fusible alloy piece 2 with lead conductors 1, 1 connected thereto; the fusible alloy piece with the flux applied thereto is stored in an insulation case 5; areas between openings of the case and the lead conductors are sealed by a room temperature curing type epoxy resin composition 6; and thereafter the sealing parts 6 are surrounded by a heat curing type epoxy resin composition 7 excellent in heat resistance as compared with the room temperature curing type epoxy resin composition.