Hello Wolfgang,
>> >  I've asked about this issue already, but maybe my cry for help was missed )
>>      
> Your chance to get an answer will be bigger when you provide a short and working example.
>
>    
Sure. This is minimal example.

\setupindenting[big,yes]
\setupfloat[figure][indentnext=yes]

\starttext

\dorecurse{1}{\input knuth \par}

\placefigure
         [inner]
     {}
     {\externalfigure[cow][width=0.5\textwidth]}

\dorecurse{1}{\input knuth \par}

\stoptext

>> >  P.S. Is there a keyword that produces an indent? (like \makeindent)
>>      
> Read Adityas TuGboat article about indenting and you will know \indentation is what you want.
>    
Thanks. Actually, i tried \indent to produce indent, but it was treated 
as wrong keyword.

Vyatcheslav