The laser scribing process is a perspective technique to produce grooves on brittle materials. In this study, we investigated the microscribing of Al2O3 ceramics with a diode-pumped Nd:YLF laser. The groove width, the groove depth and the debris height were chosen as evaluation items of the processing. Firstly, we examined the differences in the measurements of these entities by a stylus profilometer, a laser microscope, and a scanning electron microscope (SEM). According to this, the laser microscopic analysis proved to be more reliable than the stylus profilometer, but the SEM observation of the cross-section is desirable for narrow grooves. Secondly, the effects of the focal position of the laser and of the wavelength on the scribing characteristics were investigated in the fundamental mode (λ = 1047 nm) and the second (λ = 524 nm), the third (λ = 349 nm) and the fourth harmonics (λ = 262 nm). In addition, the effects of the feed rate and the number of laser scans were investigated using the third harmonic. As a result, we found that the grooves become sharp and finally remain unchanged with increasing the number of laser scans, the fourth harmonic is very suitable, and an optimal processing speed feed rate exists.