In this paper we determined the wave mode of subsecond pulses (SSP). We used data on pulses with a degree of polarization over 30%, with the sources located at -60 to +60 deg from the central meridian, for the period 2000 2002. The superposition of SSRT radio maps and MDI magnetograms has shown that radio SSP sources are typically located near the polarity inversion line of the active region magnetic field. Such an arrangement indicates that SSP sources are located at the tops of magnetic loops. The ordinary mode of electromagnetic radiation is recorded in SSP sources located from the inversion line by no less than about 10 arc sec.