An apparatus for collecting solar energy for providing thermic or electrical energy. The apparatus comprises a frame (2, 3) having a reflector means mounted therein in the form of a concave part-cylindrical mirror screen (1) of axis-symmetric cross-sectional shape for concentrating incident solar rays towards a central focal line, a solar energy utilizing means (7) placed in the hot region of the extension of the focal line along the screen (1), a drive means (20; 22) for turning the screen (1) about at least one axis, and a control circuit having a solar sensor means for actuating the drive means, for turning the screen (1) according to the movement of the sun. The solar energy utilizing means is an elongated container of transparent material which is arranged to receive a heating means (40; 43; 45) for direct utilization of the generated thermic energy for baking, roasting or cooking of food products placed in the heating means, or to receive a solar cell means (46) for producing electrical energy under the influence of solar rays concentrated in the container, and the solar sensor means comprises at least one photosensitive element (33) located in the vicinity of the caustic surface created by reflection of the solar rays when incident on the screen (1) parallel to the axis of symmetry of the cross-section of the screen.