— Appeal from a decision of the Unemployment Insurance Appeal Board, filed August 1, 1990, which ruled that claimant was disqualified from receiving unemployment insurance benefits because his employment was terminated due to misconduct.
The Unemployment Insurance Appeal Board accepted the testimony of the employer’s night audit manager that she found claimant sleeping on a couch while he was working his midnight to 8:00 a.m. shift as supervisory security officer. Although claimant denied that he had been asleep, this merely raised a question of credibility for the Board to resolve (see, Matter of Woods [Ross] 54 AD2d 515; Matter of Gadson [Catherwood] 28 AD2d 1049). In addition, sleeping while on duty was in violation of the employer’s written rules which claimant had signed. Violation of a company rule of which an employee is aware has been held to constitute misconduct (see, Matter of Sylvester [Hartnett] 143 AD2d 478; Matter of Cirlin [Ross] 70 AD2d 1030). Accordingly, the conclusion that claimant lost his employment due to misconduct is supported by substantial evidence and must be upheld (see, Matter of Rossano [Levine] 52 AD2d 1006).
*430Casey, J. P., Mikoll, Yesawich Jr., Levine and Crew III, JJ., concur. Ordered that the decision is affirmed, without costs.