This study aims to design and develop the pulsed electromagnetic fields (PEMF) device which can be utilized as an adjuvant therapy in delayed union fracture. In the first stage, Arduino-based PEMF device has been built with four main modules: pulse generator, user interface, Helmholtz coil and data acquisition system. Pulse generator allowing user to operate the physical parameters: frequency, duty cycle, burst duration and exposure duration. The Helmholtz coil could produce 1.6 mT of homogenous magnetic field. In the next stage, preliminary study was done to evaluate the effect of static magnetic field (SMF) and PEMF exposure on the healing of delayed union fracture model on Spraque Dawley (SD) rats. Six SD rats were fracturized at the femoral shaft by non-union model, then they were grouped into 2 groups, 1 (n = 3, SMFexposure, Bmax = 1.6 mT) and 2 (n = 3, PEMF exposure, Bmax = 1.6 mT frequency = 50Hz, duty cycle = 90%, burst cycle = 50%). Both groups had received the exposure for 4 hours per day and 7 hours per week. The evaluations of fracture healing were conducted by the histomorphometry analysis at 14, 21, and 28 days fracturization. PEMF group signal a better healing process through higher osseous tissue area.