A cooktop includes a knob assembly coupled to a control panel and configured to control a heating part. The knob assembly includes: a knob body disposed at a front surface of the control panel and rotating with respect to a rotation shaft extended in a front-rear direction, a knob ring disposed at a rear side of the knob body and having a diameter greater than a diameter of the knob body, and a light source part disposed at the rear side of the knob body and including one or more light sources irradiating light to the rear side of the knob body. A portion of a rear surface of the knob body includes a first reflective surface reflecting light, and a portion of a surface of the knob ring includes a second reflective surface reflecting light, the portion of the surface of the knob ring facing the knob body.