Herein, the investigation of radiation-induced defects generated in the Al/SiO₂/p-type FZ Si surface barrier detector upon irradiation with α-particles at room temperature using capacitance−voltage (C−V) and current deep-level transient spectroscopy (IDLTS) methods is conducted. The carried out C−V measurements indicate the formation of at least 8 × 10¹² cm⁻³ radiation-induced acceptor traps at the depth fairly close to that where, according to TRIM simulations, the highest concentration of vacancy-interstitial pairs is created by the incoming α-particles. The studies conducted by the current DLTS technique allow to relate the observed increase in the acceptor concentration with the near-midgap level at E _V + 0.56 eV. This level can apparently be associated with V₂O defects recognized previously to be responsible for the space−charge sign inversion in the irradiated n-type Si detectors.