A thermostat equipped with a bimetallic element sensitive to a given temperature comprises a monolithic base open at one end in which two terminals connectable to an electric circuit are inserted and precisely located, each having one end bent at a right angle and each carrying a stationary contact, an element carrying movable contacts for connecting the stationary contacts with one another, a spring housed in a seat on said base biasing the movable contact element to engage the stationary contacts, a sliding element for moving and guiding said movable contact-carrying element, a bimetallic element suitably spaced from the said sliding element for initiating movement of the sliding element in response to temperature change, and a lid which fastens the said bimetallic element to the said base with said spacing from the sliding element.