In this work ion-implanted p+/n diodes have been used as minimum ionizing particle (MIP) detectors. The diode structure is based on a 0.45$ m deep, NA= 4× 1019 cm-3 doped p+ anode, ion implanted in an n-type epilayer with thickness equal to 55$ m and nominal donor doping ND= 2× 1014 cm-3. The diode breakdown voltages were above 1000V. At 1000V reverse bias the diode leakage current was of the order of 1 nA. The punch through depletion voltage was nearing the range 220-250 V. The charge collection efficiency to minimum ionizing particle was investigated by a 90Sr β source. The pulse height spectrum was measured as a function of the reverse voltage in the range 0-605 V. At each bias point the signal was stable and reproducible, showing the absence of polarization effects. At 220 V the collected charge was 2970 e-and saturated at 3150 e-near 350 V. At the moment, this is the highest collected …