Abstract: A sensing element is adapted to monitor a temperature of a foodstuff placed within an oven cavity of a cooking utensil such as a microwave oven. The sensing element comprises a thermally-responsive element, an antenna, a double choke, and a trimmer condenser. The double choke is bent so as to provide a double compartment for causing choke operations. The double compartment contains a material the dielectric constant of which is higher than the air. A capacity of the trimmer condenser is adjustable. A resonance circuit or an oscillation circuit may be formed with the thermally-responsive element and the trimmer condenser. A metallic member is disposed adjacent to the antenna. The length of the antenna is selected as an integral multiple of about .lambda./2 (.lambda. is the wavelength of the microwaves).