The postmodern administration redefines its role as 'instance of mediation' between the citizen and politics. Public administration has a double purpose; maintaining a political position of axiological neutrality, while showing the citizen transparency and encouragement to participate in all stages of the public decision, from adopting and implementing to its evaluation. In this paper, we will argue the importance of a public administration centred on ethical values. Public good, alongside justice, can be considered a constitutive ethical value of any type of public administration, and the values of equity transparency and responsibility, as ethical operational values of a contemporary public administration system. The constitutive values make necessary the emergence and functioning of a system of social institutionsin this case, those related to public administration. The ethical operational values are those values that manage the functioning of an institutional system and establish its limitations. We bring a series of arguments for replacing the distinction between intrinsic and extrinsic values with a distinction between constitutive and operational values, in the context of social-constructionist ethics development in public administration.