An aerosol generating device comprising a resonant circuit 2. for heating an aerosol generating material, the resonant circuit comprising: an inductive element for inductively heating a susceptor arrangement to heat the aerosol generating material to thereby generate an aerosol; and a switching arrangement (M1,M2) that, in use, alternates between a first state and a second state to enable a varying current to be generated from a DC voltage supply and flow through the inductive element to cause inductive heating of the susceptor arrangement; characterised in that: the switching arrangement is configured to alternate between the first state and the second state in response to voltage oscillations within the resonant circuit which operate at a resonant frequency of the resonant circuit, whereby the varying current is maintained at the resonant frequency of the resonant circuit; the switching arrangement comprises a first transistor and a second transistor, and wherein, when the switching arrangement is in the first state the first transistor is OFF and the second transistor is ON and when the switching arrangement is in the second state the first transistor is ON and the second transistor is OFF; and the first transistor and the second transistor each comprise a first terminal for turning that transistor ON and OFF, a second terminal and a third terminal, and wherein the circuit further comprises a third transistor and a fourth transistor, and wherein the first terminal of the first transistor is connected to the second terminal of the second transistor via the third transistor and the first terminal of the second transistor is connected to the second terminal of the first transistor via the fourth transistor. an inductive element for inductively heating a susceptor arrangement to heat the aerosol generating material to thereby generate an aerosol; and a switching arrangement (M1,M2) that, in use, alternates between a first state and a second state to enable a varying current to be generated from a DC voltage supply and flow through the inductive element to cause inductive heating of the susceptor arrangement; characterised in that: the switching arrangement is configured to alternate between the first state and the second state in response to voltage oscillations within the resonant circuit which operate at a resonant frequency of the resonant circuit, whereby the varying current is maintained at the resonant frequency of the resonant circuit; the switching arrangement comprises a first transistor and a second transistor, and wherein, when the switching arrangement is in the first state the first transistor is OFF and the second transistor is ON and when the switching arrangement is in the second state the first transistor is ON and the second transistor is OFF; and the first transistor and the second transistor each comprise a first terminal for turning that transistor ON and OFF, a second terminal and a third terminal, and wherein the circuit further comprises a third transistor and a fourth transistor, and wherein the first terminal of the first transistor is connected to the second terminal of the second transistor via the third transistor and the first terminal of the second transistor is connected to the second terminal of the first transistor via the fourth transistor. the switching arrangement is configured to alternate between the first state and the second state in response to voltage oscillations within the resonant circuit which operate at a resonant frequency of the resonant circuit, whereby the varying current is maintained at the resonant frequency of the resonant circuit; the switching arrangement comprises a first transistor and a second transistor, and wherein, when the switching arrangement is in the first state the first transistor is OFF and the second transistor is ON and when the switching arrangement is in the second state the first transistor is ON and the second transistor is OFF; and the first transistor and the second transistor each comprise a first terminal for turning that transistor ON and OFF, a second terminal and a third terminal, and wherein the circuit further comprises a third transistor and a fourth transistor, and wherein the first terminal of the first transistor is connected to the second terminal of the second transistor via the third transistor and the first terminal of the second transistor is connected to the second terminal of the first transistor via the fourth transistor.