Summary: This paper is devoted to a functional analytic approach to the subelliptic oblique derivative problem for the usual Laplacian with a complex parameter \(\lambda\). We solve the long-standing open problem of the asymptotic eigenvalue distribution for the homogeneous oblique derivative problem when \(| \lambda |\) tends to \(\infty\). We prove the spectral properties of the closed realization of the Laplacian similar to the elliptic (non-degenerate) case. In the proof we make use of Boutet de Monvel calculus in order to study the resolvents and their adjoints in the framework of \(L^2\) Sobolev spaces.