Oxygen is vital for the healthy functioning of tissues and organs. For this reason, it is indispensable to monitor the oxygen saturation of the human body during daily activities in order to improve the quality of life, in the detection and tracking of respiratory diseases. Pulse Oximeter is an electro-optic device that non-invasively measures peripheral oxygen saturation and provides information about how well oxygen diffuses the tissues. Conventional devices are not suitable for daily use due to their bulky structure and designs that restrict movement. With this thesis, the design and production of a flexible reflectance type Pulse Oximeter device that is conformally adapt to measurement suite, can be used all day long and is intended for continuous measurement has been realized.