Portable seismograph (1) comprising a support and containment structure (2), a bottom portion (3) of which is made of a material having a seismic impedance value ranging between 2×105 and 4×106 kg/m2s, three sensors (4) placed orthogonally to one another, each comprising at least one electrodynamic or capacitive transducer and, attached to the bottom portion (3), a level (11) to position the support and containment structure horizontally, a control unit (5) connected to the sensors (4) for viewing, managing the acquisition mode, recording and processing the data, a power source (9), and means for coupling to the ground (12; 21) designed not perturb the seismic tremor detectable by the sensors (4).