A detailed and accurate study of the de Haas-van Alphen effect and Fermi surface of arsenic has been made by a vector-modulation technique. We find two sets of Fermi surfaces which together give the required volume compensation. The first set contains three closed, centrosymmetric pockets (β in our notation) which have a tilt angle (for the minimum area) of 86.4+/-0.1° from the trigonal axis. Their total volume is found to be (2.12+/-0.01) × 1020 carriers/cm3. The other set forms a single multiply connected surface of symmetry 3̄m and consists of six α pockets (the Berlincourt carriers) which have a tilt angle of 37.25+/-0.1°, and which are connected together by six long thin necks with a tilt of -9.6+/-0.1°. This is in excellent agreement with the recent pseudopotential calculation by Lin and Falicov if the β pockets are due to electrons at L and the multiply connected surface to holes around T. The multiplicities of the pockets are deduced from the experimental data and are supported by the consequent satisfactory agreement with the observed electronic specific heat.