To provide a functional adhesive sheet capable of laminating on various display devices including liquid crystal panels, organic EL(electroluminescent) panels, PDP(plasma display panel) panels and touch panels and exerting light-blocking and/or light-hiding ability, and to provide back light- or front light-type display devices each laminated with such a functional adhesive sheet.

The functional adhesive sheet is such as to be 30-200μm in thickness and provided with adhesive layer on one or both sides. This functional adhesive sheet is characterized by providing one side of a black base sheet 20-100μm in thickness and ≤0.1% in light transmittance with a white adhesive layer 5-100μm in thickness, containing a white pigment, ≤20% in visible light transmittance and ≥70% in the planar reflectance of 550 nm wavelength light. This functional adhesive sheet exerts optical properties including light-blocking and light-hiding abilities.