Provided is a portable power working machine in which suction of clothing to a safety guard can be reliably prevented and the amount of a portion protruding laterally from one side surface portion of a fan case can be reduced so as to enable a required air blowing performance to be obtained without causing an increase in size or weight or deterioration of the operability thereof. A suction port for inhaling air is provided on one side surface portion of a fan case of an air blower, and a safety guard is provided in the suction port. Further, the one side surface portion of the fan case has attached thereto a block prevention guard that has a top surface portion with a top surface opening facing the suction port, three leg portions for allowing the top surface opening to face the suction port with a predetermined distance therebetween, and a lattice provided in the top surface opening. Furthermore, the average opening area of apertures of the lattice in the top surface opening of the block prevention guard is larger than that of the apertures of the lattice of the safety guard.
