The present invention relates to a window grill frame for a sliding type safety grill. A guide rail is provided at a lower portion of a frame forming a safety grill frame, and a guide portion is fastened to the inside of the guide rail by screws to engage window grills in a sliding manner, thereby preventing the screws engaging the window grills to the frame from being exposed outwardly and reducing the time of assembling the safety grill. An alarm member is easily installed on the frame and the window grills installed on the frame by inserting a detection wire of the alarm member zigzag into a cable insertion groove formed in the window grills or electrically connecting the window grills by a connection member. It is possible to prevent a trespasser from intruding to the inside by engaging an insect screen or a resin panel between the window grills.
