Operating machine selected from: machine tool, handling machine, lifting machine, agricultural machine, building machine, said operating machine being provided with a control member, comprising a system of detection and analysis of bodies situated in the working space of the operating machine, the system comprising: an emitter of sound waves, a receiver of reflected sound waves, an analyzer of these reflected sound waves and an interface device between said analyzer and said control member of the operating machine, said interface device being adapted to act on the control member of the operating machine, depending on the response of the analyzer , characterized in that the analyzer of reflected sound waves is adapted to examine the reflected sound waves so that information about at least the density of the body situated in the working space of the operating machine is obtained, and wherein the analyzer of reflected sound waves is adapted to compare the obtained information with preset parameters, so that the body situated in the working space is classified as: - a non-alive body not compromising the operation of the operating machine, or - a body compromising the operation of the operating machine, for example a human body or a garment, or - a non-dangerous body, wherein the operating machine is configured to be commanded by means of the interface device to slowdown when the body situated in the working space is classified as the non-alive body not compromising the operation of the operating machine, wherein the operating machine is configured to be commanded by means of the interface device to stop when the body situated in the working space is classified as the body compromising the operation of the operating machine, wherein the operating machine is configured to be not commanded by means of the interface device when the body situated in the working space is classified as non-dangerous body. characterized in that the analyzer of reflected sound waves is adapted to examine the reflected sound waves so that information about at least the density of the body situated in the working space of the operating machine is obtained, and wherein the analyzer of reflected sound waves is adapted to compare the obtained information with preset parameters, so that the body situated in the working space is classified as: - a non-alive body not compromising the operation of the operating machine, or - a body compromising the operation of the operating machine, for example a human body or a garment, or - a non-dangerous body, - a non-alive body not compromising the operation of the operating machine, or - a body compromising the operation of the operating machine, for example a human body or a garment, or - a non-dangerous body, wherein the operating machine is configured to be commanded by means of the interface device to slowdown when the body situated in the working space is classified as the non-alive body not compromising the operation of the operating machine, wherein the operating machine is configured to be commanded by means of the interface device to stop when the body situated in the working space is classified as the body compromising the operation of the operating machine, wherein the operating machine is configured to be not commanded by means of the interface device when the body situated in the working space is classified as non-dangerous body. <EOS>