Thin foils of Copper (І) oxide (Cu₂O) have been synthesized at room temperature by using chemical colloid method of synthesis, and ascorbic acid has been applied as a reduction agent. Results of X-ray diffraction test showed that cubic phase of Cu₂O was formed without any impurity, and the sharpness of the peak of diffraction graphs proved that the percentage of crystallized nanoparticles was high. According to the results of uv-vis adsorption, it was concluded that synthesized Cu₂O nanoparticles had both spherical and cubic forms.