A device with a solid funnel shape is designed for diode-pumped slab amplifier of kW-class cw laser. The solid funnel guides the diode beam in fast axis and expands the pump beam in slow axis. The beam guiding and shaping by the funnel enhance uniformity of absorbed diode beam distribution in the slab Nd:YAG amplifier. The effect of slole angle of the funnel on transmission efficiency is also presented.