This paper reports the design, fabrication and evaluation of a reflection-type optical Rb vapor cell for chip-scale micro atomic clocks. To reduce the physical package height, the reflection-type vapor cell is developed, in which optical components can be mounted on one side of the vapor cell. A (100)-oriented Si wafer with a cut-off 9.74 toward [011] direction is used to make 45 mirrors by anisotropic wet etching. 90 mirrors are fabricated by Si deep reactive ion etching and surface planarization using H 2 annealing. Following the detection of D1 optical absorption for Rb atoms, coherent population trapping resonance was observed.