Appeals by the defendant (1) from a judgment of the County Court, Nassau County (Baker, J.), rendered July 12, 1986, convicting him of endangering the welfare of a child (two counts), upon his plea of guilty, and *619imposing sentence; and (2) by permission, from an order of the same court, dated November 26, 1986, which denied his motion pursuant to CPL 440.10 to vacate the judgment of conviction.

Ordered that the judgment and order are affirmed, and the matter is remitted to the County Court, Nassau County, for further proceedings pursuant to CPL 460.50 (5).

The defendant’s challenge to the judgment of conviction made by way of direct appeal and, by postjudgment motion, is, in essence, a nonjurisdictional attack on the sufficiency of the Grand Jury evidence (cf., People v Pelchat, 62 NY2d 97). By his plea of guilty, the defendant has waived the right to appellate review of the sufficiency of the People’s evidence (see, People v Thomas, 74 AD2d 317, affd 53 NY2d 338; cf., CPL 210.30 [6]). We note, moreover, that defendant does not challenge the validity of his plea of guilty. He therefore may not litigate, by postjudgment motion, issues rendered moot by his knowing and voluntary plea (cf., People v Thomas, supra; see, People v Peck, 24 AD2d 772). Thompson, J. P., Bracken, Niehoff and Harwood, JJ., concur.