To obtain an optical pulse evaluation device and an in-service optical pulse evaluation device, which are capable of characteristics evaluation of an optical pulse itself or a sample launched therein, in a relatively high bit-rate region. Optical pulse 42 output repeatedly from an optical pulse light source 43 at a frequency fREP passes through sample 93 n sample stage 91 to be scanned by tunable wavelength optical band pass filter 47. A detection result by photodiode 51 is input in phase detection circuit 45 accompanying with the reference frequency fREP and the result is operated by operation unit 58C of personal computer 52 to know a spectral phase and a spectral intensity of the optical pulse passed through sample 93. Correcting this by applying the operation result in the state, where sample 93 has been removed enables to evaluate characteristics such as deterioration of optical pulse 42 by using sample 93. It is also possible to evaluate a waveform of optical pulse 42 as a light source. The present invention can evaluate the optical pulse in in-service.