A description is given of an apparatus for thermoluminescence experiments with the following special features: a constant rate of warming with time obtained through a suitable cam; light detection making use of phase rectification to reject noise; a special furnace to record ``glow current curves'' simultaneously. Also, the possibility of ``flattening'' the spectral response of a photomultiplier (between 2000 and 6000 Å) is investigated and the method of calculating a suitable optical filter is outlined. The performance of the apparatus was quite satisfactory, in spite of the rather simple and relatively inexpensive construction of each part.