A recording device of the present disclosure includes a light source, an objective lens, a beam splitter, an optical element, a detector and an operation circuit. The optical element divides a light beam into a first main region, a second main region, a first main end region, a second main end region, a first sub-region, and a second sub-region. The operation circuit generates a main signal in which a first main end region signal is multiplied by a coefficient a and added to the first main region signal, and a second main signal in which a second main end region signal is multiplied by the coefficient α and added to the second main region signal.