Muonic hydrogen (μp) is a very sensitive probe of the proton structure. Laser spectroscopy of two 2S-2P transitions in μp was used to determine both the Lamb shift and the hyperfine splitting of the 2S state in μp. The rms charge radius of the proton, fm, was extracted from the Lamb shift. The Zemach radius of the proton, fm, was obtained from the 2S-hyperfine splitting. This article summarizes the previously published findings.