An X‐ray reflectometer using a laboratory X‐ray source for quick measurements of the specular X‐ray reflectivity curve is presented. It uses a bent–twisted crystal to monochromatize and focus the diverging X‐rays (Cu Kα1) from a laboratory point source onto the sample. The reflected X‐rays are recorded with a two‐dimensional detector. Reflectivity curves can be measured without rotating the sample, detector or X‐ray source during measurements. The instrument can separate the specularly reflected X‐rays from the diffuse scattering background, so low reflectivities can be measured accurately. For a gold thin film on silicon, the reflectivity down to the order of 10−6 was obtained with a measurement time of 100 s and that down to 10−5 with a measurement time of 10 s. Reflectivity curves of a silicon wafer and a liquid ethylene glycol surface are shown as well. Time‐resolved measurements of a TiO2 surface during UV irradiation are also reported.