Spanish term (edited): Ed.S

If the source text is from the US, they may have just incorrectly mixed two different things, i.e., a Master of Education and an Ed.S. (education specialist), which some universities might call a "degree" and others may not, opting instead to refer to it as a graduate-level credential earned after a master's degree (and is sometimes transferable towards doctoral degree).

I hope this helps!

THE UNIVERSITY OF ALABAMA - GRADUATE SCHOOL
Because the purposes of the Ed.S. degree may differ from those of either the Ed.D. or Ph.D., credit earned in an Ed.S. program is not automatically transferable to a doctoral program. Instead, if a holder of an Ed.S. degree enters a doctoral program at a later date, the doctoral advisory committee will decide how much of the credit earned in the Ed.S. program will be counted toward the doctorate.
http://graduate.ua.edu/academics/eds.html

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Note added at 8 hrs (2012-12-12 07:32:03 GMT)
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Oops! I meant to say "and is sometimes transferable towards a doctoral degree"; that is, some credits/courses from an Ed.S. may be accepted into some related doctoral programs. The key question is the following: where did this person do his or her studies? If they were done in the US, it's probably just a typo for Ed.S.---which is neither a master's nor a doctoral degree. That said, it does come after a master's, so it's basically an advanced graduate certificate (in the US system), hence my suggestion of "posgrado avanzado."

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Note added at 12 hrs (2012-12-12 11:55:31 GMT)
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Hello Gabriela: If it turns out that the source text is actually an abbreviation from Spanish, and a North American/US English translation might be appropriate for your target audience, you may want to consider "Master of Science in Higher Education Administration," as many (if not most) degrees in higher education---at least in the US---are in higher education administration (rather than in pedagogy, as such).