In this paper, we report an experimental investigation of subcooled and saturated pool boiling of water around a heated wire in a confined space. The experiments were carried out in a transparent miniaturized channel submerged in a transparent water container. Boiling in the miniaturized channel was brought about by an electrically-heated platinum wire (0.127mm in diameter) that was placed along the centerline of the channel. Both ends of the channel were open to the water in the container. Triangular and square channels with the hydraulic diameters ranging from 0.87mm to 10mm were tested under a wide variety of subcooling conditions ranging from 0 to 55℃ at the atmospheric pressure. Experiments were also performed by changing the channel inclination angles ranging from 0 degree (horizontal) to 90 degree (vertical). The experimental results show that the channel size has a tremendous effect on the boiling characteristics. For instance, the CHF decreased drastically as the channel size shrank from the unconfined space. The boiling curves further demonstrate that both the CHF and the heat transfer rate for the triangular channel are higher than those for the square channel having the same hydraulic diameter. It is further found that as the subcooling was increased, both the CHF and the heat transfer coefficient increased. In addition, the increase of the inclination angle (from horizontal to vertical) led to an increase in both the CHF and the heat transfer coefficient.