A microfluidic device in which microfluidic channels are embedded in a culture medium chamber and have open sides. The microfluidic device is patterned with a fluid moved along a hydrophilic surface due to capillary force, and the fluid may be rapidly and uniformly patterned along an inner corner path and a microfluidic channel. In the microfluidic device, the microfluidic channel is connected to facilitate fluid flow with a culture medium through open sides thereof and openings, and thus may provide a cell culture environment in which high gas saturation is maintained. In addition, several microfluidic devices formed on one common substrate are described. Such microfluidic devices may be manufactured of a hydrophilic engineering plastic by injection molding.