We report on a frequency resolved optical gating (FROG) system which allows the reconstruction of amplitude and phase of picosecond pulses generated by mode-locked diode laser oscillators and amplifiers. The main challenge of developing such a FROG system is the required high spectral resolution. In the spectrometer a cylindrical grating with 1200 lines/mm and a radius of curvature of 3 m is used. A width of the illuminated area of 15 cm provides in a spectral resolution exceeding 2 GHz (1.4 pm) at 460 nm. The FROG system is, thus, well suited for analyzing ps-pulses with durations of up to 80 ps and a corresponding fourier-limited spectral width of 0.017 nm.