By Medical Service Law(below, abbr as ‘Law’), the medical institutions should be established and run by ‘the doctors or the qualified persons’(below, abbr as ‘doctors’), who are permitted by the related laws. And there is a case such as non-doctors establish the institutions, hire doctors and run the institutions, or non-doctors and doctors co-establish the institutions and run the institutions. This kind of act is treated as violations under Law. When, in their running the institutions, doctors treat the patients, which means doctors give the patients the medical care in place of National Health Insurance Service(below, abbr as NHIS), doctors ask the costs of the medical care to NHIS. If the costs of the medical treatment(the medical care) do not exist or are exaggerated, the act of asking the costs will constitute Fraud. But if doctors in such institutions described above treat the patients fairly, and then ask NHIS the costs with no falsity or exaggeration, does that act constitute Fraud? This kind of act has not been treated as Fraud until 2013. But from the second half of 2013, this kind of act has been prosecuted as Fraud. Is that prosecution right? Is it guilty as Fraud? Medical treatment has a broad effecion on the health and welfare of people, so business mind should be excluded from medical treatment. And Law has regulations on the qualification of establishing the institutions to prevent the substantial distortion of medical treatment. But if doctors’ treatment is true, which means there is no falsity or exaggeration in medical treatment, then there can not exist the substantial distortion. And the article 57 ① of Law regulates ‘trick or the other undue method’, but I think this kind of act does not conform to the article 57 ① of Law. And even if this kind of act conforms to the article 57 ① of Law, it does not mean that it is Fraud. Because Fraud has the strong character of mala in se, transcendentally the act of Fraud should be evaluated anti-social and immoral. But this kind of act can not be assessed anti-social and immoral transcendentally. And the criminal control on this kind of act can not be the fundamental measure to prevent the financial aggravation of NHIS. And because this kind of act is treated as violations under Law, if the punishment of Fraud is added, it could violate the principle of proportion or principle of subsidiarity.