An apparatus for depositing poly(p-xylylene) onto a component, the apparatus comprising: - a radio-frequency electrical power supply configured to operate at a frequency between 1 and 100 MHz; - a deposition chamber; - a platen disposed inside the deposition chamber and comprising an electrically conductive material, wherein the platen is electrically connected to the electrical power supply and configured to support a component; - an electrode, either disposed in the deposition chamber or defined by the deposition chamber wherein the electrode is electrically insulated from the platen; - a pyrolysis oven, comprising a first heating element configured to heat the pyrolysis oven to a first elevated temperature sufficient to cause pyrolysis of a poly(p-xylylene) dimer; - a vaporiser oven, comprising a second heating element configured to heat the vaporiser oven to a second elevated temperature sufficient to cause evaporation of the poly(p-xylylene) dimer; - a first feed means comprising a conduit which extends between the pyrolysis oven and the deposition chamber and being configured to feed a poly(p-xylylene) monomer to the platen; and - a second feed means comprising a conduit which extends between the vaporiser oven and the pyrolysis oven and being configured to feed the poly(p-xylylene) dimer into the pyrolysis oven, wherein (i) the platen is configured to support a component comprising an electrically conductive material and the electrical power supply is configured to apply electrical power to the electrically conductive component supported by the platen at a power of between 0.0001 Watts/cm 2 and 10 Watt/cm 2 such that a plasma is generated that surrounds the component and ionizes and/or activates the poly(p-xylylene) monomer; or wherein (ii) the platen is configured to support a component consisting of an electrically insulating material and the platen comprises a plate configured to receive the component thereon and the electrical power supply is configured to apply electrical power to the platen at a power of between 0.0001 Watts/cm 2 and 10 Watt/cm 2 such that an electrical field is generated, which is able to penetrate through the component and to create a plasma that surrounds the component and ionizes and/or activates the poly(p-xylylene) monomer. - a radio-frequency electrical power supply configured to operate at a frequency between 1 and 100 MHz; - a deposition chamber; - a platen disposed inside the deposition chamber and comprising an electrically conductive material, wherein the platen is electrically connected to the electrical power supply and configured to support a component; - an electrode, either disposed in the deposition chamber or defined by the deposition chamber wherein the electrode is electrically insulated from the platen; - a pyrolysis oven, comprising a first heating element configured to heat the pyrolysis oven to a first elevated temperature sufficient to cause pyrolysis of a poly(p-xylylene) dimer; - a vaporiser oven, comprising a second heating element configured to heat the vaporiser oven to a second elevated temperature sufficient to cause evaporation of the poly(p-xylylene) dimer; - a first feed means comprising a conduit which extends between the pyrolysis oven and the deposition chamber and being configured to feed a poly(p-xylylene) monomer to the platen; and - a second feed means comprising a conduit which extends between the vaporiser oven and the pyrolysis oven and being configured to feed the poly(p-xylylene) dimer into the pyrolysis oven,