In this publication we used a molecular dynamics computer simulation in order to get more detailed insights into the adsorption process of monododecyl pentaethylene glycol (C₁₂E₅) surfactants. We investigated the surface between water and air at infinite small surfactant concentrations. Measured in respect to the surface normal vector the average tilt angle of the C₁₂ chain was found to be of the order of 67.4°±18.3°. For the polar pentaethylene glycol chains we observed tilt angles of 78.0°±8.5°. These results indicate that the molecules are lying nearly flat on the water surface. This observation is in fairly good agreement with neutron reflection experiments of C₁₂E₃ and also with a previously performed simulation of sodium dodecylsulfate. Additionally, it turned out that the conformations of C₁₂E₅ surfactant molecules adsorbed at the air/water interface are similar to the molecular arrangements of C₁₂E₅ in the vacuum phase. This holds, at least, for the regime of infinitely small surfactant concentrations.