The article features a new technique of work motivation diagnostics based on the new developed concept of motivational task. A motivational task is a tool for selfappraisal in the field of motivational objects allowing further reconstruction of motivational space. The conditions of the motivational task resolution have been implemented in the diagnostic procedure “Motivational Map”. The diagnostics procedure consists in multiple visual appraisal forms of 16 motivational objects (J.Nuttin) within a dimensional graphic space determined by 6 evaluation scales. To indicate the geometric patterns that reflect the relationship between motivational objects the term subjective motivation space is used, based on the definition of subjective psychological space in modern models of multidimensional scaling. Conditions of motivational tasks are as follows: ranking of motivational objects, determining the subjective centre of motivational space, multiple comparative evaluation of motivational objects, successive refinement of estimates of motivational objects, adjusting the motivational space with due account of placing high priority motivational object. Approbation of new assessment technique was conducted using a sample of 206 financial experts and included two series which had the test and the retest stages. These results were compared with the scores received using the results of standard questionnaires. The construct validity of the methodology was assessed by means of the regression analysis. The scales used in the standard methodologies of work motivation assessment served as the independent variables, while the parameters registered by the developed methodology served as the dependent variables. In the course of validity analysis, 32 highly important regression models were established. The results of psychometric verification of validity and reliability are presented in this paper.