We have developed a confocal 3D-XRF spectrometer in combination with polycapillary X-ray lenses and a laboratory X-ray source. The depth resolutions of the 3D-XRF configuration estimated by scanning of Au and Cr thin foils were approximately 50 μm for AuLα, and 100 μm for CrKα, respectively. The capacity of the depth-sensitive analysis of the confocal setup was investigated by scanning a thick plastic reference sample concluding trace metals of Ti, Cr, Co and Pb. The depth sensitivity in deeper region was significantly decreased than that in the surface region because of the absorption of X-ray irradiation and X-ray fluorescence in the material. The calculated LLD values of Cr at each depth were 9.4 mg/kg at 300 μm, 23 mg/kg at 500 μm, 38 mg/kg at 700 μm, 77 g/kg at 900 μm, and 110 mg/kg at 1100 μm, respectively. 3D elemental analysis with the confocal XRF setup was demonstrated for an electrical Cu cable covered with PVC. The 3D elemental images agreed well with the actual distributions of the sample. The confocal 3D-XRF has a great advantage for 3D elemental analysis as well as nondestructive depth analysis at ambient pressure.