A magneto-optic trap (MOT) is a powerful tool with which a large number of neutral atoms can be trapped in space with laser beams and inhomogeneous magnetic field. In this study we have constructed a MOT setup and have trapped rubidium atoms from the background rubidium atoms at room temperature in a high vacuum chamber. Rubidium atoms were loaded into the magneto-optic trap with two diode lasers: A high-power diode laser (TA-100 from TUI, 400 mW max.) was used for 6 trapping laser beams and a low-power diode laser (Vortex from New focus, 10 mW) for a repumping laser. Saturation absorption spectroscopy was used to stabilize the laser frequency at the $D_2$ line (780.1 nm) of $^{85}Rb$ atom. High vacuum, in the order of $10^{-8}$ Torr, was maintained inside the chamber with an ion pump, initiated by a turbo molecular pump. A pair of anti-Helmholtz coils was used to produce inhomogeneous quadrupole magnetic field. As a result, our MOT was maintained stably for thirty minutes when the magnetic field gradient was set at 6 G/cm and the laser frequencies were all stabilized. We observed change of MOT by varying the frequency detuning, laser intensity, current of the anti-Helmholtz coils, etc. Trap lifetime was estimated from a sequence of CCD pictures of MOT, which were taken while the trap was being loaded. The lifetime was 109 ± 3.4 ms, which is reasonably consistent with the theoretical estimate of 145 ms. The density of the trapped atoms, and consequently the total number of atoms, were measured from the probe laser trasmission. The MOT diameter was estimated to be 2 mm from corrected CCD absorption images. As a result, we obtained the total atom number of $1.2×10^7$ atoms and the density of $2.9×10^9 atoms/㎤$.