styling element inside class material ui

Find some kind of answer after a while! Styling Field component itself is impossible because it's made of other elements, but you can style elements which are inside materialUI component:

shopForm: {
    textAlign : 'center',
'& input' :{
    width: '60%',
    color:'grey'
   },
'& label':{
  fontSize:'15px'
}

so you have to find which element you want to style first and then give style to the parent's class.

<Grid 
  item
  lg={4}
  className={classes.shopForm}
>
  <Field
    name="name"
    type="text"
    label="name"
    component={TextField}
  />
  <Field
    name="plaque"
    type="text"
    label="plaque"
    component={TextField}
  />
  <Field
    name="unit"
    type="text"
    label="unit"
    component={TextField}
  />
  <Field
    name="text"
    type="text"
    label="text"
    component={TextField}
    multiline
    row={3}
  />
</Grid>

Update

as I didn't found an answer anywhere, to style class inside other class(only work if class is from classes object)

parentClass:{
   ...styling 
           '& $childClass': {
               ...styling 
        },

        // in my case I needed psuedo-class
           '&:hover': {
               '& $childClass': {
                   ...styling 
            },}
}

and if child class is not from material-ui classes and is string

  parentClass:{
           '& .childClass': {
               ...styling 
        },

}